320 MEMOIRS OF THE NUTTALL ORNITHOLOGICAL CLUB. 



the flocks are subject to frequent and interesting mutations of membership. 

 During the early part of August they are nearly sure to contain — in addi- 

 tion to the omnipresent Chickadees and Downy Woodpeckers — Wood Pewees, 

 Least Flycatchers, Scarlet Tanagers, Red-eyed Vireos, Yellow-throated Vireos, 

 Black and White Creepers, Nashville Warblers, Black-throated Green Warblers, 

 and Oven-birds. There is usually a larger variety than this and occasionally one 

 may meet with a gathering which comprises fifteen or twenty different species 

 represented by seventy-five or a hundred individuals. On such occasions it is 

 difficult to identify all the members of the flock, for they are constantly in motion 

 and also concealed, during much of the time, among dense foliage, while most of 

 them are in immature plumage. They may be seen to the best advantage when 

 found on the borders of some sunny opening hemmed in on every side by pines, 

 hemlocks, oaks, maples and birches or by alders, viburnums and other tall 

 shrubs. Sometimes there will be a dozen or more birds collected in the top of 

 a single tree or bush and perhaps thrice as many within a space of a few square 

 rods. As they hop and flit from twig to twig they keep the foliage constantly 

 agitated. Prematurely ripened, yellow leaves are dislodged by their movements 

 and sent fluttering to the ground. In the early morning they shake down many 

 a shower of sparkling dewdrops. They are incessantly chirping, scolding and 

 calling to one another and every now and then an adult male utters, more or less 

 brokenly and listlessly, a few notes of its spring song. Still lighter sounds 

 which they produce, such as that of their wings striking against the leaves, or 

 of their mandibles snapped at flying insects, may be heard at intervals when the 

 air is calm. Altogether it is a somewhat bewildering as well as most fascinating 

 experience to be closely surrounded by such a swarm of active, graceful and 

 attractively colored little creatures most of whom are so trustful by nature or so 

 busily engaged in searching for food that they pay scarce any heed to the near 

 presence of the human observer. They are far too restless, however, to remain 

 long in any one spot. Suddenly, without apparent incentive but probably at a 

 signal of some kind given by one of the older birds, the members of the flock 

 begin leaving the place in quick succession, all moving off in the same general 

 direction and so rapidly that it is not always easy to keep up with them. 

 Many disappear abruptly and mysteriously or are lost to sight among the foliage 

 after flying only a few yards. Some swing from tree to tree in deep, gliding 

 curves or loops. Others take longer and more direct flights. Still others — the 

 younger and giddier birds, no doubt — pursue one another madly through and 

 over the treetops or just above the surface of the ground, turning, doubling, 

 twisting and performing all manner of wonderful and intricate evolutions. 

 Within the space of a minute or less the entire host may range beyond sight and 

 hearing unless promptly pursued. But its members are sure to reassemble at 

 no great distance to resume their tireless search for food. 



